The long term of this study is to provide detailed mechanistic understanding of Wilson's disease (WD). WD is a severe and potentially fatal human disorder of copper homeostasis, caused by mutations in the copper transporter ATP7B. The disease is associated with copper overload in tissues, particularly in the liver, and a wide spectrum of hepatic, neurologic, and psychiatric abnormalities. Currently, specific molecular pathways through which copper triggers WD are poorly understood. The proposed studies will use a multidisciplinary approach based on modern methodologies to identify biochemical and cellular events that lead to the onset and progression of WD. The experiments measuring oxidation state of glutathione and proteins will determine whether in WD copper acts by modifying the redox environment of cellular compartments (Specific Aim 1). The role of hnRNP A2 in cell response to copper overload will be determined by characterizing its intracellular localization, interacting proteins, and a subset of transcripts affected by hnRNPA2 up-regulation (Specific Aim 2). Metabolic changes in the brain of Atp7b-/- mice will be characterized by corelating time-dependent copper distribution with changes in lipids and mRNA profiles at different stages of the disease (Specific Aim 3). Cell injury and behavior changes will be evaluated in conjunctions with analysis of molecular and metabolic changes.